Why Do We Need Sleep (and So Much of It?)

We all know that sleep plays an essential role in our lives, and is one of our most basic needs as a human being. We spend almost a full third of our lives sleeping, and some serious consequences to sleep deprivation have been discovered through research and sleep studies. Yes, it’s definitely safe to say that sleep is as necessary to us as water and food, but why do we spend so much time doing it each and every night?

To put it simply, no one really knows yet. After multiple sleep studies and years of research into the need for sleep and why we actually enter a state of unconsciousness each night, the best info that has been discovered up until this point is the fact that we sleep because we get sleepy.

Seems almost too simple, but the one thing that scientists and sleep experts can agree upon is the fact that losing eight hours each night to sleep is absolutely crucial to our health and wellbeing, and it always has been. Lying unconscious for extended periods of time made our ancestors vulnerable to attacks from enemies and wild animals, yet sleep still seemed to outweigh the risk.

For years, scientists have been trying to clear the largest hurdle to understanding sleep and why we do it – what happens to our brains when we sleep. Thankfully, new methods have emerged to help sleep experts learn what type of activity our brains go through when sleeping, and that is helping us to better understand why the heck we sleep in the first place.

One study that was published in Brain Research hints that there is mounting evidence to show that sleep is used to “consolidate memories,” allowing us to convert short-term memory into long-term memory. This study found that while we sleep, our brains gather and process the information we’ve learned that day by opening biochemical pathways in the brain via calcium-mediated neurons. This appears to be critical to our health and possibly the real reason why we sleep, as the “network reorganization” that occurs during sleep can’t happen any other time, and must be done when normal processes like sensory processing have been suspended.

Still other sleep studies have suggested that our need for snoozing is all about taking out the trash. Researchers at the University of Rochester conducted a study that shows during sleep, our cerebral spinal fluid is moved around our brains to clear out the waste chemicals that have been created during the day by normal cell activity. Scientists point to this as being the reason we sleep due to the fact that this “house cleaning” can only happen when we’re asleep, much like memory consolidation.

Yet another study has indicated that the reason we sleep comes down to the simple demand for energy that our bodies must deal with each day. Published in PLOS Biology, this study states that sleep has always been used to allow man and beast to save energy, since predator performance and prey availability occurred during different times throughout the day. But researchers do admit that this theory needs further investigation, as it fails to explain the occurrence of REM sleep, which usually results in an increase of energy usage.

So the bottom line here is that while we don’t have a simple and straight answer for why we fall into an unconscious and paralyzed state each night for about eight hours, all of the scientists and health experts can agree on the fact that sleep is a very big part of what keeps us happy and healthy, and it should be given priority in our lives.